Lapping machine



March 13, 1928. 1,662,137

K. E. SUMMERS LAPPING MACHINE March 13, 1928.

1,662,137 K. E. SUMMERS LAPPING MACHINE Filed March 4, 1924 2 Sheets-.Sheet 2 Patented Mar. 13, 1928.

UNITED STATES PATENT OFFICE.

KENNETH E. SUMMERS, OF WESTBORO, MASSACHUSETTS, ASSIGNOR TO IBETHEL- PLAYER CO., OF WESTBORO, MASSACHUSETTS, A COPARTNERSHIP CONSISTING F JOSEPH N. BETHEL AND SIDNEY PLAYER. i

LAPPING- MACHINE.

.Application led March 4, 1924. Serial No. 696,870.

This invention relates to a machine particularly designed for lapping internal conical surfaces. Such surfaces are required in certain types of ball and roller bea-rings and for other purposes in which a very smooth accurate surface is necessary. 1t has been the common practice to grind such surfaces, but a ground surface has been found not sufficiently accurate to be satisfactory.

It is the object of my invention to provide a machine by which an internal conical surface may be accurately lapped, and to provide a satisfactory finish with a minimum expenditure of time and labor.

To the attainment of this object, I provide a lapping head having a plurality of lapping elements which are freely rotatable against the surface to be lapped and which are movable axially while in rolling contact with the l work. In the preferred form. I provide a cam for reciprocating the lrolling elements, together with means for rotating the cam and the lapping head at different speeds.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more partieularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a sectional side elevation of my improved lapping machine;

Fig. 2 is lan enlarged sectional elevation of the lapping head;

Fig. 3 is a side elevation. of the cam for reciprocating the lapping elements; and

Fig. 4 is a detail i-'iew'of a modification to be described.

Referring to the drawings, l have shown a lapping machine comprising ay base to which is secured a post or bracket 11 upon which a work support 12 is keyed for vertical sliding movement. A hand lever 13 has a pin and slot connection at 14 with the work suppe-rt 12.

The work W may be secured to 'the work support in any convenient manner, as by clamps 15, and is preferably held from rotation thereon with its center accurately aligned with the center of the lapping head tobe described. The work support and the means for raising and lowering the same, as herein shown, is illustrative only, and any other suitable devices may be substituted therefor.

A standard 16 is secured to the base 10 and supports a bearing bracket 17. A slee-ve 18 is freely rotatable in the bracket 17 and a shaft 19 is freely rotatable in the sleeve 18. Suitable mechanism is provided for rotating the sleeve 18 and shaft 19, such mechanism, as herein shown, comprising pulleys 20 and 21 and aI belt 22 for the sleeve 18 and pulleys 23 and 24 and a belt 25 for the shaft 19.

The pulleys 21 and 24 are fixed to al vertical shaft 26 rotatable in fixed bearings and driven from a driveshaft 27 by means of a worm 28 and worm wheel 29. may be rotated in any convenient manner, as by fast and loose pulleys 30 and 31 beltdriven from any convenient source of power.

It will be noted that the p-airs of pulleys 20 and 21, and 23 and 24 differ substantially in relative sizes, so that the sleeve 18 and shaft 19 are rotated at different speeds.

A lapping head 33 is pinned or otherwise secured to a shank 34 having al tapered driving fit in the lower end of the shaft 19. A plurality of lapping elements or rolls 35 are rotatably mounted on spindles 36 which are disposed about the axis of the shaft 19 at such an angle that the spindles 36 will be substantially parallel to the conical internal surface of the work.

A bushing 37 is secured to the lower end of each spindle 36 and provides a shoulder to hold the lapping roll 35 from axial movement on the spindle. The bushing 37 also provides a bearing surface for the lower end of the spindle and rotates in one of a series of bushings 38 fixed in the lower end of the lapping head 33. The upper portion of each spindle 36 is slidable and rotatable in one of a series of bea-ring bushings 39, also secured in the hea-d 33.

At their lower ends, the spindles 36 project into an oil chamber 40 formed in a cap 41 secu-red to the lower end of the sha-nk 34. This oil chamber provides lubrication for the lower spindle bearings-and also prevents dust and dirt from reaching the lower ends of the spindle 36.

At their upper ends, the spindles 36 are provided with heads 42 which engage the lower surface of a cam 43 keyed to the lower The shaft 27 end of the rotatable sleeve 18. Springs 44 surround the spindles 36 and engage shoulders 45 below the heads 42, forcing the spindles yieldingly upward against the cam 43.

Having described the construction of my improved lapping machine, the operation thereof will be apparent. The machine being placed in operation, the sleeve 18 and shaft 19 will be rotated at different speeds, thus causing a progressive reciprocation of the spindles 36 while the spindles are also rotated bodily about the axis of the shaft 19. The work is accurately centered and secured on the work support 12 and is raised by the lever 13 until the rolls 35 engage the inner conical surfaces thereof. As the work is held in such engagement, the lapping elements are caused to roll around the inner conical surface of the work and at the same time they are reciprocatcd in directions parallel to the lines of contactI with the work. Suitable abrasive and lubricant will be provided during the lapping operation and a smooth accurate finished surface will thus be quickly produced.

In Fig. 4, I have indicated the substitution of a small grinding roll in place of each lapping roll 35, this grinding roll being provided with a. bushing 51 having a bearing on the spindle 36. When. the work comes tothe machine in a particularly Irough or unlinished condition, I find it desirable to subject the work first to the action of grinding rolls 50 before using the lapping rolls 35. The grinding rolls 50 roll in contact with the work and are reciprocated parallel thereto as lpreviously described, and act more rapidly to ring the surface to an approximately finished condition, after which the lapping rolls 35 complete the operation.

When used for lapping, the rolls 35 are preferably of east iron or of some soft metal. The same mechanism may be also used for burnishinnf by usino' hardened steel rolls in place of tlie soft rolls used in lapping.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what I claim is 1. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mounted in said head and each having free rolling contact with said internal surface, means to rotate said head, and means to reciprocate said lapping elelnents in said head alongr separate paths, each path being substantially axial of its lapping element.

Q. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mounted in said head, means to rotate said head, and a cam to successively move said elements axially.

3. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mountedin said head, means to rotate said head, a cam to successively move said elements axially, and additional means to rotate said cam at a different speed.

4. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mounted in said head, means to rotate said head, and means to successively move said elements axially.

5. A machine for lapping internal surfaces, comprising a lapping head, a plurality of rotatable lapping elements movably mounted in lsaid head, means to rotate said head. means to successively move said elements axially and additional meansl to rotate said last mentioned means at a different speed.

(3. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mounted in said head, means to rotate said head, a cam to successively move said elements axially, and springs for said lapping elements effective to force said elements yieldingly upward against said cam.

7. A machine for lapping internal conical surfaces comprising a lapping head. means to rotate said head, a plurality of lapping elementsI each having free rolling contact with said internal surface, spindles for said elements, said spindles having bearings in said lapping head and being supported for free rotation therein with their axes substantially parallel to the surface to be lapped, and means to reciprocate said spindles in said bearings.

8. A machine for lapping internal surfaces comprising a lapping head, a plurality of rotatable lapping elements movably mounted in said head and each having free rolling contacts with said internal surface, means to rotate said head, means to reciprocate said lapping elements in said head, means to hold and support the Work, and means to cause a relative approach of said work and lapping head.

9. A machine for lapping internal conical surfaces comprising a plurality of freely rotatable lapping elements, means to support said elements with' their axes substantially parallel to the surface to be lapped, means to cause said elements to roll against said conical surface, and means to reciprocate said elements axially as they are rolled.

10. A machine for lapping internal conical surfaces comprising a plurality of freely rotatable lapping elements, means to sup Ort said elements with their axes substantially parallel to the surface to be lapped, means to cause said elements to roll against said conical surface, means to reciprocate said elements axially as they are rolled, a Work support, and means to cause relative movement of said lapping elements and said work support to effect engagement of the work thereby.

11. In a lapping machine, ashaft, a lapping head secured thereto, a sleeve surroundlng said shaft, means to rotate said sleeve and shaft at different speeds, a cam on said sleeve, a plurality of lapping elements mounted in said head and inclined to the axis thereof, and means to cause said lapping elements to yieldingly engage said cam for reciprocation thereby.

12. In a machine for lapping internal conical surfaces, a plurality of lapping elements each rotatable about an axis substantially parallel to the surface to be lapped, means to rotate all of said elements as a unit about an axis perpendicular to the plane of the work, and means to simultaneously reciprocate each element axially While in rolling contact with the Work.

13. A machine for lapping internal conical surfaces comprising a lapping head,

means to rotate said head, a plurality of lapping elements, spindles for said elements, said spindles having bearings in said lapping head and being supported therein with their .axes substantially parallel to the surface to be lapped, and means to reciprocate said spindles 1n said bearings, said lapping head having an oil chamber at the lower end thereof' into which said spindles project.4

14. A machine for lapping internal conical surfaces comprising a lapping head, means to rotate said head, a plurality of lap ping rolls, spindles for said rolls, bearings for said spindles in said head above and below7 said rolls and disposed in annular series about the axis ofsaid head, said bearings and spindles being inclined with' respect to the axis of said head, means to rotate said head, and means to reciprocate said spindles in said head, as said head is rotated.

In testimony whereof I have hereunto aixed my signature.

KENNETH E. SUMMERS. 

